The novella was the basis of a film adaptation in 1974, the post-apocalyptic science fiction film of the same name, directed by L. Q. Jones working in collaboration with Harlan Ellison. The film was also distributed after the initial run under the names Psycho Boy and His Killer Dog, Mad Don, and Apocalypse: 2024, among other titles.

The novella and the film adaptation have the same alternate timeline setting. In this, President John F. Kennedy survived the assassination attempt in 1963 and in his terms of office and that of the other Kennedys, the advancement of technology was concentrated on and billions of dollars poured into it instead of the space race. Technology flourished in the 1960s far faster than it did in our timeline as indeed within a few years even surpassed the point we are at now. Androids became common household servants in the United States before the end of the decade. Extensive research was done in the fields of extra sensory perception, telepathy, and animal intelligence which are all proved possible.

This new form of technological race only intensified the Cold War, which had begun in June 1950 with the Soviet Union and the People's Republic of China, eventually becoming an arms race. The world became divided along the lines of the "Western Bloc" and the "Eastern Bloc". World War III broke out and was fought by conventional means very similar to World War II, yet lasting decades, with both sides suffering heavy losses and neither gaining the upper hand. World War III ended in an uneasy truce—the "Vatican Armistice"—in March 1983. Tensions continued for the next 25 years and the global economy never recovered. In 2007, global negotiations finally broke down and World War IV broke out. This time the war was fought with nuclear weapons and only lasted five days, just long enough for the nuclear missiles to leave their silos on both sides. Civilization was almost entirely obliterated, leaving the surface of the Earth reduced to a desolate, irradiated, desert wasteland.

The year in which the novella and the film take place is 2024. The few survivors who remain above ground must forage and fight for food, clean water, clothes, weapons, ammunition and women. Of these necessities, women are the rarest; most survivors are male because while the males were off fighting in the wars, their enemies bombed and destroyed their homes. Among these survivors it has become a rule of dog eat dog.

The main character, Vic (played by Don Johnson in the film), is an 18-year-old boy born in 2006 in the ruins of Phoenix, Arizona. In the novel and the film, Vic concentrates on stealing food and fulfilling his sexual needs. He is quite base, because he lost both of his parents in the nuclear war, has no formal education and doesn't understand ethics or morality. Satisfying his carnal desires remains Vic's main motivation throughout the story. He is accompanied by a well-read and wise-cracking telepathic dog named Blood, an "experienced female provider" by his advanced senses of smell and hearing. Blood's main motivation is food, notably popcorn (his favourite) which Vic is able to provide by theft or by purchasing from various vendors in the wastelands. Blood needs Vic because, as a side-effect of the genetic engineering which gave him telepathic abilities, Blood does not have the instincts to forage for food. In the film, Blood is portrayed by Tiger and voiced by veteran Tim McIntire.

Vic and Blood scavenge the deserts of the Southwestern United States, stealing for a living and evading bands of marauders, berserk androids and mutants. Vic looks up to Blood as a teacher and a father figure and Blood views Vic with equal fondness as a protégé, even though at times Blood is frustrated with Vic's rebellious nature and unwillingness to learn. Although they argue over trivial matters and threaten each other, nothing ever comes of it and in the end both agree (reluctantly) that they need each other to survive. They have also been together since Vic was born and Blood a puppy.

In addition to locating women for Vic to rape, Blood has the unenviable task of trying to educate Vic and keep him safe from harm. Blood is the result of genetic experimentation, which resulted in an intelligent canine mutation with telepathic abilities. The only human Blood can communicate with is Vic, who Blood calls "Albert" as a "term of endearment." In the later graphic novel Vic and Blood, Blood explains: "I get such a kick out of calling him Albert – after Albert Payson Terhune, who wrote all those stupid dog books in which we noble creatures were pets, always being saved by some sappy human - it is my best gambit to make him scream." It is said in the novel that Albert is Vic's real name but Vic doesn't like it.

Blood's opinion of the human race is not generally positive and Blood is somewhat misanthropic. His opinion of humans may have something to do with the fact that Blood is possibly the most intelligent and learned living thing left in the world and he looks down upon the "stupidity" of humans. Blood notes that "human sex is an ugly thing". Blood has a positive outlook on life in general and believes in a place untouched by nuclear radiation that he heard about from a police dog. Blood refers to this place at various times as "Over The Hill" and the "Promised Land", where "deer and the antelope play and it's warm and clean and we can relax and have fun and grow food right out of the ground." Blood wants to look for "Over The Hill" with Vic, but Vic won't entertain it. Vic states that this is as good as it gets and there is no "Over The Hill."

The film begins with Vic sneaking through foothills in search of a bunker. An unseen voice is heard advising Vic, which is soon revealed to be his telepathic dog, Blood. When he reaches the bunker, he finds his quarry, a woman, severely mutilated and raped. He is angry and disappointed, because he is unwilling to have sex with a dead body that is so disheveled. In his sexual frustration, Blood and Vic get into several arguments, and the quirks of their relationship are revealed. Blood and Vic continue their travels and stumble upon a slave driver who's heading an excavation into another bunker. His slaves begin to pull out cans of food, and when no one is paying attention, Vic runs up and steals several cans and runs away. With their new found wealth, Blood and Vic travel to a makeshift settlement with a working projector and permanent residents - a rarity in the wasteland. While there, Blood claims to smell a woman, which excites Vic. The pair track her to a large underground warehouse.

The girl turns out to be Quilla June Holmes (portrayed by Susanne Benton in the film) the scheming and seductive daughter of the head of a large underground vault named Topeka's committee, Lou Craddock (portrayed by Jason Robards in the film), who has been sent by her father to the surface to bait Vic into much needed "service". Blood takes an immediate dislike to Quilla, sensing something wrong. He warns Vic, who ignores him. After saving Quilla's life from a band of raiders and then some mutants called "screamers", Vic spends an amorous night with her. In the morning she knocks Vic unconscious and flees. She had told Vic about where she lives and also deliberately left an access card to the vault door so that he could follow her. Vic, taken by the idea of women and sex, leaves Blood despite his pleading and pursues the young lady into "downunder".